In many applications, it is desirable to have a common broadband transmit and receive antenna. A circulator may be used to provide isolation between transmit and receive subsystems using a common antenna. However, due to antenna reflectance, a circulator does not fully provide isolation between transmit and receive subsystems. Even with the use of matching networks, antenna reflectance cannot completely be eliminated. Therefore, there is a need for a device that can increase the transmit-to-receive isolation of a system using a common antenna.